Stop mechanism for sawmill set-works.



J. WALTON. STOP MECHANISM FOR SAWMILL SET WORKS.

\ APPLICATION FILED MALE, 1904. 899,579.

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Patented Sept. 29, 1908.-

WITNESSES INVENTOR.

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J. WALTON. 4 STOP MECHANISM ron SAWMILL sB'r WORKS.

APPLICATION IILIID MAR. 5. 1904.

899,579.. Patented Sept. 29, 1908.

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WITNESSES By I -TON v ATTORNEK.

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I UNITED STATES- PATENT OFFICE.

.TOHN WALTON, OF'MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-GHALMERS COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF NEW JERSEY.

STOP MECHANISM FOR SAWMILL SET-WORKS.

Specification of Letters Patent.

Patented Sept. 29, 1908.

Application filed March 5, 1904. Serial No. 196,700.

To all whom it may concern:

Be it known that I, JOHN WALTON, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and. State of Wisconsin, have invented certain new and useful Improvements in Stop Mechanism for Sawmill Set-Works, of which the following is a specification.

My invention relates to stop mechanism for sawmill set works and its objects are to provide a stoppingdevice for the motion of the stop arm and to positively limit its motion in both directions automatically without shock.

.In the accompanying drawings,Figure 1 is a view of the essential parts of a set works showing my im rovement. Fig. 2 is a detailed view of t e adjusting lever and stop. Fig. 3 is a plan view of Fig. 1.

' The set shaft 1 carries a ratchet wheel 2, and is connected with a head block by rack and gear, or any other well known manner. The pawl arms 3, 3, carry pawls 40, 41,-for engagement with the teeth of the ratchet wheel 2, to turn it in one direction only. The links 4, 4, connect these pawl arms with the rock arms 5, 5, mounted on the rocker shaft 6. This rocker shaft is driven by a bevel gear 7., meshing with two bevel gears 8, 9, loosely mounted on a shaft 10, driven by a band wheel 11, or other appropriate driving means. These gears. are provided with internal clutch surfaces and are alternately connected to the shaft by means of clutches 12, 13, operated by clutch lever 14 through the connections shown, thus permitting rotation of the rocker-shaft 6 in either direction. The stop arm 15 is mounted on the.

rocker-shaft 6 and oscillateswith thelatter. Two stops including movable members 16, 17, are provided for the movement in either direction. The movable member 16 is mounted in a fixed art of the segment 18, which forms part of file frame and carries the segment 19 provided with ratchet teeth. The movable member 17 is mounted on a stop lever 20, provided with a pawl for looking the lever by the ratchet teeth in different positions. The movable members 16, 17, are mounted on pins 28, 26, forming supports for the movable members and passing respectively loosely through the segment frame 18 and stop lever 20, and carry friction rollers 22, 23, at their outer ends. The stops thus include the movable members 16, 17

and their supports or pins 28, 26. The springs 27, 21 are mounted on the projecting end of the pins 28, 26, carrying the. movable members 16, 17, and have their ends connected respectively to the segment frame 18 and stop lever 20, and to the pins 28, 26, in such a manner as to yieldingly resist vibratory movement of the movable members 16, 1 7, away from projecting lugs 24, 25, provided respectively onthe segment frame 18 and stop lever 20. When free to do so, the springs 27, 21, cause the movable members 16, 17, to be positioned against the lugs 24, 25. The outer end of the stop arm 15 is shaped on both sides to conform to the groove of the friction rollers.

The operation of the device is as follows: The stop lever 20 is first adjusted in accordance with the required amount of set. From the position shown in Fig. 1 of the drawing, the clutch 12 is thrown into engagement with stop arm 15-is vibrated in the direction of the arrow. At the same time the upper pawl 40 is retracted in the same direction and the lower pawl 41 operates to rotate the set shaft 1. When the stop arm 15 reachesthe roller 23 of movable member 17 yielding resistance to farther motion will be encountered. due to tension of the spring 21. As the action proceeds, resistance becomes greater and greater the more nearly the movable member 17 and the stop arm 15 approach a position at right angles to each other. At this position the resisting force is infinite, that is, the stop arm 15 comes to a dead stop. At this point the clutch 12 is thrown out, but should this not be done soon enough, the friction between the clutch surfaces will be overcome and the shaft 10.with clutch 12, will turn independently of the gears 8, 7, and rocker-shaft 6, which remain stationary. The operation in action, and the upper pawl 40 entering into engagement with the ratchet wheel 2, and thus turning the set shaft 1 through link 4 and rock arm 5.

The line of pressure on the stop from the stop arm 15 is normal to the stop arm. The point of application of this pressure as the operation proceeds, is at an increasing radial distance from the axis of the stop arm 15. A line of resistance to this pressure through the movable member-16,-17 of the stop and the the other direction is precisely similar. The clutch 13, gear 9, and stop 16, coming 1nto the gear 8, and the rocker-shaft 6 with the I support 26, 28 is radial from the aXis of the movable member 16, 17.

It will thus be seen that a stop is provided having a yielding resistance increasing as the mechanism approaches the end of its motion. By this means the momentum of the moving parts is gradually absorbed, thus allowing the apparatus to come to a stop without shock or The stop is independent of the actuating I desire it to be understood that the appara-- tus shown is merely illustrative and that the invention can be carried out by other means.

What Ielaim as new and desire to secure by Letters Patent of the United States is,

1. In a saw mill set works, a rocker-shaft, a stop arm on the rocker shaft, actuating means for the rocker shaft, and stop means independent of the actuating means andv comprising-a movable member and a support, so arranged that the line of pressure on the stop from the stop arm and a line of resist ance to such pressure through the member and the support are first at an angle to each other but in the course of movement of such member become parallel or in line thus act ing to offer gradually increasing resistance to the motion of the rocker shaft near the limits of its motion and to positively limit its extent of motion.

2. In a saw mill set works, a set shaft, op erating means for the set shaft, a stop for the operating means comprising a spring subjected member movable angularly to the line of pressure on the stop, and a support for the member, the action being such as to diminish to Zero the angularity of the line of pressure on the stop to a line of resistance to such pressure through the member and the support, thus acting to offer gradually increasing resistance to the motion of the operating means and to positively limit its extent of motion.

3. In a saw mill set works, a set shaft, operating means for the set shaft, a swinging arm co-acting with the operating means, and a stop for the arm comprising a movable member and a support for the member, the action being such that the arm is engaged by the stop at a point increasing in radial distance from the aXis of the arm as the operation proceeds.

4. In a saw mill set works, a rocker-shaft, means for alternately actuating the rockershaft, a setshaft, connections between the rocker-shaft and the set-shaft for operating the latter in a constant direction, a stop arm on the rocker-shaft, a stop on each side of the stop arm, each stop including a pivotally mounted arm and a friction roller mounted on the free end of the arm, the stop arm contaeting with the friction roller near the limits of its motion.

5. In a saw mill set works, a rocker-shaft, a stop arm on the rocker-shaft, a stop eoacting with the stop arm and pivotally mounted on the frame, a stop lever loosely mounted on the rocker-shaft and a second stop co-acting with the stop arm and pivotally mounted on the stop lever, the stops being pivotally mounted within the limits of motion of the stop arm.

6. In a saw mill set works, a rocker-shaft, a stop arm on the rocker-shaft, a stop coacting with the stop arm and pivotally mounted on the frame, a stop lever loosely mounted on the rocker-shaft and a second stop co-acting with the stop arm and pivotally mounted on the stop lever, springs re sisting outward swinging of the stops, and lugs on the frame and stop lever for limiting inward swinging of the stops.

7. In a saw mill set works, a rocker-shaft, a stop arm on the rocker-shaft, and a pivoted stop on each side of the slop-arm adapted to gradually resist and positively limit the motion of the rocker-shaft through. the stop arm.

8. In a saw mill set works, a set shaft, means for operating the set shaft, a member actuated. by the operating means, and a stop swinging during engagement with the said member.

9. In a saw mill set works, a rocker shaft, a stop arm on the rocker shaft, actuating means for the rocker shaft, and stop means not included in the actuating means and comprising a movable member and a support, so arranged that the line of pressure on the stop from the stop arm and a line of resistance to such pressure through the member and the support are first at an angle to each other but in the course of movement of such member become parallel or in line thus acting to offer gradually increasing resistance to the motion of the rocker shaft near the limit of its motion and to positively limit its extent of motion, substantially as described.

10. In a saw mill set works, a rocker shaft, a stop arm on the rocker shaft, and a swinging stop on each side of the stop arm adapted to gradually resist and positively limit the motion of the rocker shaft through the stop arm, substantially as described.

11. In a saw mill set works, a rocker shaft, a stop arm on the rocker shaft, a stop eoaeting with the stop arm and pi\ 'otally mounted. on the frame, a stop lever loosely mounted on the rocker shaft and a second stop co-acting with the stop arm and pivot- .l. l O

ally mounted on the stop lever, the stops being mounted to swing within, the limits of motion of the stop arm, substantially as described.

a stop arm on the rocker shaft, actuating means for the rocker shaft, and a stop not forming a part of the actuating means and comprising a movable member and a support so arranged that the line of pressure on the movable member of the stop from the stop arm. and the line joining the point of ap lication' of pressure on the movable mem er and the point of support thereof, are first at an angle to each other but finally become parallel or in line, thus acting to offer gradthereof, thus acting to ofier gradual ually increasing resistance to the motion of the rocker shaft and to positively limit its movement. r

14. In a saw mill set works, a set shaft, operating means for the set shaft, a stop for the operating means comprising a spring subj eoted angularly movable member and a support for said member, the action bein such as to diminish to zero the an le of the line of pressure on the stop to the ine joining the point of application of pressure on the spring subjected member and the point of sulpport creasing resistance to the motion of the operating means and to positively limit its movement.

In testimony whereof I affix my signature inzpresence of two witnesses.

JOHN WALTON. Witnesses:

CHAS. KOMSOHLIES, Jr., Louis E. STREET. 

